KDL

0.2.1

This is the API reference of the Orocos Kinematics and Dynamics Library (KDL)

intro

A simple use case for a SerialChain kinematic :

• creation and allocation : create and define a simple 2 dof serial kinematic chain.

    		SerialChain* chain = SerialChain("MY_KINEMATICS",0,2);
    		chain->addJoint( new JointTransX(Frame::Identity()));
    		chain->addJoint( new JointTransY(Frame::Identity()));
   		setLastJointToEE(Frame(Rotation::Identity(),Vector(0,0,0.5)));
    

• The object using the forward position kinematics looks like :

       class User {
  		Jnt2CartPos*   jnt2cartpos;
  		std::vector<double> q;
  		Frame F_base_ee;
  	 public:
  		User(KinematicFamily* kin) :
  			jnt2cartpos(kin->createJnt2CartPos()),
  			q(kin->nrOfJoints())
  		{
  			if (jnt2cartpos==0) {
  				// a Jnt2CartPos instance does not exist for this kinematic family.
  			}
  		}
  		~User() {
  			delete jnt2cartpos;
  		}
  		void calculate() {
  			int result = jnt2cartpos->evaluate(q);
  			if (result !=0) {
  				// could not calculate the transformation..
  			}
  			jnt2cartpos->getFrame(0,F_base_ee);
  		}
       }
    

  Note that the calculate() method can be called real-time. All allocation and deallocation is done in the constructor and destructor. The User object does not make any assumptions on the kinematic family that is used.

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